Overlaying Virtual Broadcast Domains On An Underlying Physical Network

1. A computer-implemented method, comprising: determining that a network device is a member of two or more member virtual groups of network devices, wherein each network device in a virtual group of the two or more member virtual groups shares a common property, wherein the common property is a property that network devices on different networks have in common; receiving, at the network device, a broadcast message; determining a characteristic of the broadcast message, wherein the broadcast message is only transmitted to virtual groups of network devices that can receive a broadcast message with the characteristic; determining which of the two or more member virtual groups to transmit the broadcast message to using the characteristic; and transmitting the broadcast message, wherein the broadcast message is received based on the determined characteristic of the broadcast message.

2. The method of claim 1 , wherein the characteristic of the broadcast message is a transmission rule that indicates a list of virtual groups that the broadcast message may be forwarded to.

3. The method of claim 2 , wherein the transmission rule is in a header of the broadcast message.

4. The method of claim 1 , wherein the characteristic includes one of the group of: content of the broadcast message, a time when the broadcast message was sent, and a location of a device that transmitted the broadcast message.

5. The method of claim 1 , further comprising: determining that a network device in one of the two or more member virtual groups ceases to share the common property with the other network devices of the virtual group; and dynamically updating the virtual group.

6. The method of claim 1 , wherein when the broadcast message is received by a subset of network devices in a virtual group, the broadcast message is forwarded to the other members of the virtual group.

7. A computing device, comprising: one or more processors; and a memory having instructions stored thereon, which when executed by the one or more processors, cause the computing device to perform operations including: determining that a network device is a member of two or more member virtual groups of network devices, wherein each network device in a virtual group of the two or more member virtual groups shares a common property, wherein the common property is a property that network devices on different networks have in common; receiving, at the network device, a broadcast message; determining a characteristic of the broadcast message, wherein the broadcast message is only transmitted to virtual groups of network devices that can receive a broadcast message with the characteristic; determining which of the two or more member virtual groups to transmit the broadcast message to using the characteristic; and transmitting the broadcast message, wherein the broadcast message is received based on the determined characteristic of the broadcast message.

8. The computing device of claim 7 , wherein the characteristic of the broadcast message is a transmission rule that indicates a list of virtual groups that the broadcast message may be forwarded to.

9. The computing device of claim 8 , wherein the transmission rule is in a header of the broadcast message.

10. The computing device of claim 7 , wherein the characteristic includes one of the group of: content of the broadcast message, a time when the broadcast message was sent, and a location of a device that transmitted the broadcast message.

11. The computing device of claim 7 , further comprising instructions, which when executed by the one or more processors, cause the computing device to perform operations including: determining that a network device in one of the two or more member virtual groups ceases to share the common property with the other network devices of the virtual group; and dynamically updating the virtual group.

12. The computing device of claim 7 , wherein when the broadcast message is received by a subset of network devices in a virtual group, the broadcast message is forwarded to the other members of the virtual group.

13. A computer-program product tangibly embodied in a nontransitory machine-readable storage medium, including instructions configured to cause a data processing apparatus to: determine that a network device is a member of two or more member virtual groups of network devices, wherein each network device in a virtual group of the two or more member virtual groups shares a common property, wherein the common property is a property that network devices on different networks have in common; receive at the network device, a broadcast message; determine a characteristic of the broadcast message, wherein the broadcast message is only transmitted to virtual groups of network devices that can receive a broadcast message with the characteristic; determine which of the two or more member virtual groups to transmit the broadcast message to using the characteristic; and transmit the broadcast message, wherein the broadcast message is received based on the determined characteristic of the broadcast message.

14. The computer-program product of claim 13 , wherein the characteristic of the broadcast message is a transmission rule that indicates a list of virtual groups that the broadcast message may be forwarded to.

15. The computer-program product of claim 14 , wherein the transmission rule is in a header of the broadcast message.

16. The computer-program product of claim 13 , wherein the characteristic includes one of the group of: content of the broadcast message, a time when the broadcast message was sent, and a location of a device that transmitted the broadcast message.

17. The computer-program product of claim 13 , further comprising instructions configured to cause the data processing apparatus to: determine that a network device in one of the two or more member virtual groups ceases to share the common property with the other network devices of the virtual group; and dynamically updating the virtual group.

18. The computer-program product of claim 13 , wherein when the broadcast message is received by a subset of network devices in a virtual group, the broadcast message is forwarded to the other members of the virtual group.